<!DOCTYPE html>
<html lang="en">
  <head>
    <meta charset="UTF-8" />
    <meta http-equiv="X-UA-Compatible" content="IE=edge" />
    <meta name="viewport" content="width=device-width, initial-scale=1.0" />
    <title>Document</title>
  </head>
  <body>
    <div class="content">
      <div class="left"></div>
      <div class="mid"></div>
      <div class="right"></div>
    </div>
  </body>
  <style>
    * {
      margin: 0;
      padding: 0;
    }
    .content {
      display: flex;
      height: 200px;
    }
    .left {
      /* flex: 0 0 30%; */
      flex-basis: 30%;
      /* width: 30vw; */
      background-color: red;
    }
    .mid {
      flex: auto;
      background-color: yellow;
    }
    .right {
      width: 160px;
      background-color: blue;
    }
  </style>
</html>
